Contactor Coil Spike Suppression Diode

A coil spike suppression diode is a protection device across the contactor coil. Energizing the contactor coil creates a magnetic field that forces the solenoid arm to engage the contacts. When the contactor is turned off, the magnetic field collapses causing a back “voltage spike” that can damage the controller. The diode safely suppresses this energy.

Note: Pre-Charge Resisters and Coil Spike Suppression Diodes are required with all Alltrax controllers but are not used with Curtis AC controllers or Sevcon controllers

Installation

The Diode goes across the contactor coil with the band towards the positive side of the coil.